started up my o2 a4 quattro and heard a faint ticking sound. i popped the hood and traced it back to a "silvery" round part at the left back (facing front of car) corner of the head. it is about 1-1/2" in diameter, what is this and is it normal to tick (i doubt it!).

help please, i need info etc.

thanks in advance - chad

 

Is it behind the head? Sounds like the combi valve. It would have a small vacuum line going out the right side if so. Not sure about the clicking though. You sure it's not coming from inside the head? If you didn't use a stethoscope or something it's hard to know exactly where it's coming from.

 

Can you take a picture and post it?

 

definately not the head very pronounced and when i cover it with my hand it muffles it. i will take pic tonight if i can unless someone has a exploded view for me. it does have a 3/4" or so hose coming off and going beside the head (on the turbo side) and disappears near turbo.